Bypass apparatus of oil-cooler and controlling method thereof

ABSTRACT

A bypass apparatus of an oil cooler is provided that includes an oil pump that is configured to supply oil in an oil pan to an engine through an oil cooler and an oil filter. In addition, a solenoid valve is connected to front and rear ends of the oil cooler and is configured to change a circulation path of oil by being opened or closed by a controller.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority of Korean Patent Application Number 10-2014-0112091 filed on Aug. 27, 2014, the entire contents of which application are incorporated herein for all purposes by this reference.

BACKGROUND

1. Field of the Invention

The present invention relates to a bypass apparatus of an oil cooler that changes a circulation path of oil, using a solenoid valve, to reduce a pressure difference in an oil cooler, and a method of controlling the same.

2. Description of the Related Art

Engines are supplied with engine oil for lubrication while being operated. In particular, engine oil is pumped up by an oil pump from an oil pan under an engine and then supplied to the engine sequentially using an oil cooler and an oil filter. The oil cooler is a component configured to cool oil that circulates after absorbing heat by cooling an engine, oil dissipates heat while returning back to an oil pan in common wet type engines and engine oil is cooled by dissipating heat in an oil pan in many engines. However, the oil may not be sufficiently cooled by dissipating heat in an oil pan, particularly, in engines continuously operating at a substantially high speed or in small-sized light engines. Accordingly, there is a need for an oil cooler configured to cool engine oil. Such an oil cooler is usually disposed under or behind a radiator for cooling water and cools engine oil through heat exchange with cold cooling water for cooling an engine, and is usually integrated with an oil cleaner.

Further, a solenoid valve is disposed to allow oil to bypass the oil cooler, if necessary. Such a solenoid valve, which is provided to improve fuel efficiency by reducing a pressure difference of an oil cooler, allows oil to bypass an oil cooler in an oil temperature-rising section and enables oil to be cooled by allowing oil to pass through an oil cooler when the temperature of the oil is elevated. However, when bypassing is unexpectedly performed when the temperature of oil increases, the rate of increase in oil temperature decreases.

The foregoing is intended merely to aid in the understanding of the background of the present invention, and is not intended to mean that the present invention falls within the purview of the related art that is already known to those skilled in the art.

SUMMARY

Accordingly, the present invention provides a bypass apparatus of an oil cooler which prevents reduction of the rate of increase in oil temperature even when bypassing is performed while temperature is increasing, and a method of controlling the bypass apparatus.

According to one aspect of the present invention, a bypass apparatus of an oil cooler may include: an oil pump configured to supply oil in an oil pan to an engine through an oil cooler and an oil filter; and a solenoid valve connected to front and rear ends of the oil cooler and configured to change a circulation path of oil by being opened or closed by a controller.

The controller may be configured to open the solenoid valve to supply oil to the engine without passing through the oil cooler, when the engine accelerates. The controller may also be configured to close the solenoid valve to supply oil to the engine through the oil cooler, when the engine decelerates. The controller may be configured to open the solenoid valve to supply oil to the engine without passing through the oil cooler, when the engine is maintained at a predetermined speed and driving torque is to be reduced. The controller may be configured to close the solenoid valve to supply oil to the engine through the oil cooler, when the engine is maintained at a predetermined speed and oil temperature is to be increased.

According to another aspect of the present invention, a method of controlling a bypass apparatus of an oil cooler may include: detecting, by a controller, whether a speed of a running vehicle has changed; detecting, by the controller, whether a vehicle is being accelerated, when a speed change is detected; and bypassing, by the controller, the oil cooler by opening a solenoid valve of the bypass apparatus, when acceleration is determined.

When a speed change is not detected (e.g., the speed is maintained at a predetermined speed) and the controller determines that driving torque is to be reduced, the bypassing of the oil cooler by opening the solenoid valve may be performed. When a speed change is not detected and the controller determines that oil temperature is to be increased, the solenoid valve may be closed. In response to determining that an engine decelerates, the solenoid valve may be closed.

According to the bypass apparatus of an oil cooler and the method of controlling the bypass apparatus, since a solenoid valve allowing oil supplied to an engine to pass through or bypass an oil cooler is provided and controlled electronically by a controller, it may be possible to actively control whether to bypass the oil cooler based on the operation state of the engine. Therefore, it may be possible to control a solenoid valve more accurately and rapidly based on the running state of a vehicle, as compared with the related art.

Further, when an engine is accelerating, oil bypasses an oil cooler and the driving torque of an oil pump decreases, to thus improve the fuel efficiency, and when an engine is decelerating, oil passes through an oil cooler to increase the rate of the oil temperature increase by heat exchange between cooling water and the oil; therefore, the engine may be maintained in the optimum operation state. In addition, since the oil pump used herein is a variable oil pump, the driving torque of an oil pump that increases due to closing of a solenoid valve may be converted so that driving energy that is wasted when the engine decelerates is available, and accordingly, fuel efficiency may be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is an exemplary diagram showing when a solenoid valve of a bypass apparatus of an oil cooler is open according to an exemplary embodiment of the present invention;

FIG. 2 is an exemplary diagram showing when the solenoid valve shown in FIG. 1 is closed according to an exemplary embodiment of the present invention;

FIG. 3 is an exemplary flowchart showing a method of controlling a bypass apparatus of an oil cooler according to an exemplary embodiment of the present invention; and

FIG. 4 is an exemplary graph showing a solenoid valve opened or closed in accordance with a vehicle speed, when the bypass apparatus of an oil cooler is used according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION

It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, combustion, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuels derived from resources other than petroleum).

Although exemplary embodiment is described as using a plurality of units to perform the exemplary process, it is understood that the exemplary processes may also be performed by one or plurality of modules. Additionally, it is understood that the term controller/control unit refers to a hardware device that includes a memory and a processor. The memory is configured to store the modules and the processor is specifically configured to execute said modules to perform one or more processes which are described further below.

Furthermore, control logic of the present invention may be embodied as non-transitory computer readable media on a computer readable medium containing executable program instructions executed by a processor, controller/control unit or the like. Examples of the computer readable mediums include, but are not limited to, ROM, RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash drives, smart cards and optical data storage devices. The computer readable recording medium can also be distributed in network coupled computer systems so that the computer readable media is stored and executed in a distributed fashion, e.g., by a telematics server or a Controller Area Network (CAN).

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/of” includes any and all combinations of one or more of the associated listed items.

Hereinbelow, a bypass apparatus of an oil cooler and a method of controlling the bypass apparatus according to exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is an exemplary diagram showing when a solenoid valve 600 of a bypass apparatus of an oil cooler is open and FIG. 2 is an exemplary diagram showing when the solenoid valve 600 shown in FIG. 1 is closed. A bypass apparatus of an oil cooler according to an exemplary embodiment of the present invention may include: an oil pump 200 configured to supply oil in an oil pan 100 to an engine through an oil cooler 300 and an oil filter 400; and a solenoid valve 600 connected to the front and rear ends of the oil cooler 300 and configured to change a circulation path of oil by being opened or closed by a controller 700.

In the present exemplary embodiment, the oil pump 200 may be a variable oil pump. Assuming that the engine 500 is a diesel engine, unless oil passes through the oil cooler 300, the rate of increase in oil temperature decreases and more mechanical friction may be caused in the engine 500, such that a variable oil pump is provided to prevent such a reverse effect by reducing oil pressure. In particular, the oil pump 200 may operate as a main gallery feedback type, in which the discharge pressure of the oil pump 200 decreases as much as a pressure difference of the oil cooler 300, when the oil cooler 300 is bypassed through the solenoid valve 600, with main gallery pressure maintained, such that driving torque of the oil pump 200 decreases. Accordingly, the difference between the amount of increasing friction due to delay of the temperature increase and the amount of decreasing friction by the oil pump 200 is less than zero, thus causing the driving torque to reduce throughout the oil supply system.

The solenoid valve 600 may be an NC type (Normal Close Type), maintained closed while inactivated. However, power may be supplied by the controller 700 to open the solenoid valve 600 and allow oil to bypass the oil cooler 300. In other words, unlike a wax type of solenoid value as taught by related art in which a valve is opened or closed by wax expanding/contracting in accordance with temperature, in the bypass apparatus of an oil cooler of the present invention, the controller 700 may be configured to apply power to the solenoid valve based on the operation state of the engine 500 to open or close the solenoid valve 600. Therefore, since the solenoid valve 600 may be actively operated in accordance with the operation state of the engine 500, it may be possible to achieve more accurate control according to the state of the engine 500 and to improve fuel efficiency.

The operation of the controller 700 for operating the bypass apparatus of an oil cooler of the present invention is described in detail. The controller 700 may be configured to detect the operation state of the engine 500 based on various signals. For example, as taught in the related art, it may be possible to detect whether the engine 500 accelerates, decelerates, or maintains a substantially constant speed, by sensing the amount of acceleration pedal engagement or the amount of opening of a throttle valve or by directly detecting the vehicle speed. Detecting the state of a vehicle by the controller 700 is known in the art, so it is not described in detail herein.

When the engine 500 accelerates, the controller 700 may be configured to open the solenoid valve 600 by applying power to the solenoid valve 600. Accordingly, the oil from the oil pump 200 may be supplied to the engine 500 through the oil filter 400 to reduce the driving torque of the oil pump 200 and improve fuel efficiency accordingly. When the engine 500 decelerates, the controller 700 may be configured to prevent power from being applied to the solenoid valve 600 and the solenoid valve 600 may be maintained closed to supply oil to the engine 500 sequentially through the oil cooler 300 and the oil filter 400. Accordingly, the temperature of the oil may increase more rapidly due to heat exchange between cooling water and the oil in the oil cooler 300.

When the engine 500 maintains a substantially constant speed, the controller 700 may be configured to select an advantageous speed for the operation of the engine from reducing the driving torque and increasing the oil temperature in accordance with the operation state of the engine 500 and then may be configured to determine whether to open or close the solenoid valve 600. Accordingly, when the controller 700 determines that the engine 500 maintains a substantially constant speed and it is advantageous to reduce the driving torque, the controller may be configured open the solenoid valve 600 to supply oil to the engine 500 without passing through the oil cooler 300. When the controller 700 determines that the engine 500 accelerates and it is advantageous to increase the oil temperature, the controller may be configured to close the solenoid valve 600 to supply oil to the engine 500 through the oil cooler 300.

FIG. 3 is an exemplary flowchart showing a method of controlling a bypass apparatus of an oil cooler and FIG. 4 is an exemplary graph showing the solenoid valve 600 opened or closed in accordance with a vehicle speed, when the bypass apparatus of an oil cooler is used. A method of controlling a bypass apparatus of an oil cooler, which is a method of controlling the bypass apparatus of an oil cooler defined in claim 1, may include: detecting, by the controller 700, whether the speed of a running vehicle has changed (S100); detecting, by the controller 700, whether the vehicle is being accelerated, when a speed change is detected (S300); and bypassing, by the controller 700, the oil cooler by opening the solenoid valve 600, when acceleration is determined (S500).

In the detection of whether the speed of a running vehicle has changed (S100), the controller 700 may be configured to detect whether a speed has changed with the engine 500 in operation, and then when a speed change is detected, the controller 700 may be configured to detect whether the vehicle is accelerated or decelerated. In response to determining that the vehicle is being accelerated, the controller 700 may be configured to perform bypassing (S500) to apply power to open the solenoid valve 600. In response to determining that the vehicle is being decelerated, the solenoid valve 600 may be maintained as closed and oil may be supplied to the engine 500 through the oil cooler 300.

When a speed change is not detected and the controller 700 determines that it is advantageous to reduce the driving torque based on the operation of the engine 500, the bypassing (S500) for opening the solenoid valve 600 may be performed. Further, when the controller does not detect a speed change detected and determines that it is advantageous to increase the oil temperature based on the operation of the engine 500, the solenoid valve 600 may be maintained as closed.

According to the bypass apparatus of an oil cooler, since a solenoid valve allowing oil that is supplied to an engine to pass through or bypass an oil cooler is provided and controlled electronically by a controller, it may be possible to actively control whether to bypass the oil cooler based on the operation state of the engine Therefore, it may be possible to operate a solenoid valve more accurately and rapidly based on the running state of a vehicle, as compared with the related art.

Further, when an engine is accelerating, oil bypasses an oil cooler and the driving torque of an oil pump decreases, to improve fuel efficiency, and when an engine is decelerating, oil passes through an oil cooler so that the oil temperature is increased faster by heat exchange between cooling water and the oil; therefore, the engine may be maintained in the optimum operation state. In addition, since the oil pump used herein may be a variable oil pump, the driving torque of an oil pump that increases due to closing of a solenoid valve may be converted so that driving energy that is wasted when the engine decelerates may be available, and accordingly, fuel efficiency may be improved.

Although an exemplary embodiment of the present invention has been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. 

What is claimed is:
 1. A bypass apparatus of an oil cooler, comprising: an oil pump configured to supply oil in an oil pan to an engine through an oil cooler and an oil filter; and a solenoid valve connected to front and rear ends of the oil cooler and configured to change a circulation path of oil by being opened or closed by a controller.
 2. The apparatus of claim 1, wherein the controller is configured to open the solenoid valve to supply oil to the engine without passing through the oil cooler, when the engine accelerates.
 3. The apparatus of claim 1, wherein the controller is configured to close the solenoid valve to supply oil to the engine through the oil cooler, when the engine decelerates.
 4. The apparatus of claim 1, wherein the controller is configured to open the solenoid valve to supply oil to the engine without passing through the oil cooler, when the engine is maintained at a predetermined speed and driving torque is to be reduced.
 5. The apparatus of claim 1, wherein the controller is configured to close the solenoid valve to supply oil to the engine through the oil cooler, when the engine is maintained at a predetermined speed and oil temperature is to be increased.
 6. A method of controlling a bypass apparatus of an oil cooler of claim 1, comprising: detecting, by the controller, whether a speed of a running vehicle has changed; detecting, by the controller, whether a vehicle is being accelerated, when a speed change is detected; and bypassing, by the controller, the oil cooler by opening a solenoid valve of the bypass apparatus, when acceleration is determined.
 7. The method of claim 6, wherein when a speed change is not detected and it is determined that driving torque is to be reduced, the bypassing of the oil cooler is performed, by the controller, by opening the solenoid valve.
 8. The method of claim 6, wherein when a speed change is not detected and it is determined that oil temperature is to be increased, the solenoid valve is closed by the controller.
 9. The method of claim 6, wherein in response to determining that an engine decelerates the solenoid valve is closed by the controller. 